Digentetic Trematodes in Dicentrarchus labrax cultured in Egypt: Prevalence, Clinical Features, Body Condition, and Histopathology

Authors
Salah M. Aly; Sayed Abou El-Gheit; Amr Fadel; Habiba Essam El-Din
Abstract
The current work aimed to study the types and seasonal occurrence of digenetic trematodes in D. labrax cultured in Egypt. A total number of 1800 D. labrax, (150/season- 600/farm) of average weight 95.14±10.37 gm were collected from three Egyptian farms during 2019. Four digeneans were isolated from the gastrointestinal tract; Metadena crassulata Derogenes varicus, Acanthostomum spiniceps, and Diplomonorchis sphaerovarium. The highest infection rate was detected in Farm 2 (30.16 %), specifically at spring (27.76% ), where the range of water temperature was 21.12- 24.63 oC, and salinity 15.85-32.34 ppt. The infected fish were apparently healthy, except in heavy infestation where body weakness and anemia of the internal organs were evident. The infected fingerling recoded the lowest condition factor (0.98) and mean parasitic intensity of 3.9, but higher values were noticed in juvenile, adult, and broodstock. Moreover, weak linear regression was reported between infection intensity and weight (R=0.91), fish length (R=0.964), and condition factor (0.956). Remarkable pathological alterations were observed in the intestine of infected fish, including edema, aggregation of inflammatory cells, mucinous degeneration and sloughed necrotic areas. Therefore, preventive and control measures are recommended to avoid such infections that potentially influence the health status and productivity of infected fishes